pub fn borrow_demo() {
    let v1 = vec!["a", "b", "c"];
    borrow_vec(&v1);
    println!("{:?}", v1);

    let mut v2 = vec![0, 1, 2, 3, 4, 5];
    borrow_mut(&mut v2);
    println!("{:?}", v2);
}
fn borrow_vec(v: &Vec<&str>) {
    println!("{:?}", v);
}

fn borrow_mut(v: &mut Vec<i32>) {
    v.push(10);
}
